AB0929 Is there a correlation between skin severity and joint activity in Psoriatic Arthritis (PsA)?
Authors: G. Aldabie, M. Sutton, D. D. Gladman
Journal: Annals of the Rheumatic Diseases (2022)

Background The majority if patients with PsA present with skin manifestations first. Few studies have examined the relationship between severity of skin and joint manifestations, but the results have been variable. Objectives To assess the correlation between the extent and severity of skin psoriasis and musculoskeletal manifestations of PsA over time. Methods This study is a retrospective analysis of prospectively collected data at a single center cohort study of patients who enrolled within 12 months of PsA diagnosis from 2000-2020. Patients are assessed according to a standard protocol which includes demographics, clinical assessment including skin and joint assessments, laboratory evaluation at 6–12-month intervals and radiographs every 2 years. Skin severity is measured by the PASI score, joint disease severity is measured by the number of tender and swollen joints. Axial disease was defined by the presence of bilateral grade sacroiliitis or unilateral grade 3 or 4. The Bath Ankylosing Spondylitis Metrology Index (BASMI) was also measured. Spearman correlations were calculated between PASI scores and joint counts and BASMI (in patients with axial disease). Multivariable analysis was done using negative binomial model for the joint counts and a linear regression for BASMI. This preliminary analysis includes only the baseline information. Results 397 patients were included. Characteristics are shown in the Table 1. There was a correlation significant correlation between PASI score and the active joint count (AJC) (ρ 0.14, p=0.0095), swollen joint count (ρ 0.15, p=0.0071). Among the patients with axial disease there was a strong correlation between the PASI and BASMI scores ((ρ 0.58, p=0.0001). Table 1. Baseline characteristics of 397 patients Variable Mean (SD)*, Number (%)** N=397 Age (years) 44.97 (13.01)* PsA duration (years) 0.43 (0.66)* Psoriasis duration (years) 14.64 (13.65)* Married 236 (60.5)** Smoker ever 193 (48.7)** Alcohol intake 246 (62.3)** Employed 309 (78.4)** Post secondary education 277 (71.0)** BMI 29.21 (8.85)* PASI 6.11 (9.03)* Nail 238 (61.2)** Active joint count (tender ± swollen) 7.3 (13/15)* Swollen joint count 2.96 (4.93)* Axial disease 53 (17.8%)** Treatment level None/NSAIDS only 272 (68.2)** DMARDS ± NSAIDs 98 (24.7)** Biologics ± DMARDs 27 (6.80)** Multivariable analysis for AJC revealed traditional DMARDs (0.85 p=0.000). PASI score when patients were on no therapy (0.02 p=0.01) and those on biologics 0.04 p&lt;0.05) were associated with higher AJC. Similarly for swollen joints the use of traditional DMARDs (0.85 P0.00), and the PASI score in those taking biologic DMARDs (0.07 p=0.003) were associated with higher swollen joint count. In patients with axial disease Age (0/05, p=0.004), PASI score in patients on no treatment (0.06 p=0.000) or those taking biologics (0.28 p=0.000) were associated with higher BASMI scores. Conclusion In patients presenting within 12 months of diagnosis of PsA, there is a correlation between the severity of skin and joint disease. Further studies will assess whether this correlation persists over time. Acknowledgements The Toronto Psoriatic Arthritis Research Program is supported by a grant from the Krembil Foundation. Disclosure of Interests Ghaydaa Aldabie: None declared, Mitchell Sutton: None declared, Dafna D Gladman Consultant of: AstraZeneca